My Math Forum  

Go Back   My Math Forum > Science Forums > Physics

Physics Physics Forum


Thanks Tree1Thanks
  • 1 Post By topsquark
Reply
 
LinkBack Thread Tools Display Modes
September 3rd, 2015, 09:30 AM   #1
Member
 
Joined: Aug 2014
From: Lithuania

Posts: 60
Thanks: 3

Magnetic fields

Three endless wires are positioned as shown in the picture. The middle wire has two times smaller current. The distance of neighboring wires is a. Find all points on dotted lines in which the magnetic field is equal to 0.



Here's my try:

Magnetic fields created by the wires (in order from left to right):

$\displaystyle B_1=\frac{μ_o2I}{2πr_1}$

$\displaystyle B_2=\frac{μ_oI}{2πr_2}$

$\displaystyle B_3=\frac{μ_o2I}{2πr_3}$


$\displaystyle \vec B = \vec B_1+\vec B_2+\vec B_3$

$\displaystyle B_1+B_3=B_2$

$\displaystyle \frac{2}{r_1}+\frac{2}{r_3}=\frac{1}{r_2}$

$\displaystyle \frac{r_1r_3}{2r_3+2r_1}=r_2$

Last edited by kaspis245; September 3rd, 2015 at 09:41 AM.
kaspis245 is offline  
 
September 3rd, 2015, 10:15 AM   #2
Math Team
 
topsquark's Avatar
 
Joined: May 2013
From: The Astral plane

Posts: 2,038
Thanks: 812

Math Focus: Wibbly wobbly timey-wimey stuff.
So far so good. If we consider a point on, say, the horizontal line, then assuming r1 is between wires 1 and 2 we get that r2 = a - r1, and r3 = r2 + a = 2a - r1.

-Dan
Thanks from kaspis245
topsquark is offline  
September 4th, 2015, 09:40 AM   #3
Member
 
Joined: Aug 2014
From: Lithuania

Posts: 60
Thanks: 3

Thanks, I did solve it.
kaspis245 is offline  
Reply

  My Math Forum > Science Forums > Physics

Tags
fields, magnetic



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Do magnets\ magnetic fields become weaker when exposed to para magnetic objects? Ganesh Ujwal Physics 1 December 27th, 2014 05:14 AM
MAgnetic Force guru123 Physics 2 October 10th, 2011 07:31 AM
Urgent Question about passing through magnetic fields! FishFace Physics 0 April 20th, 2011 11:47 AM
Magnetic forces TsAmE Physics 0 October 30th, 2010 05:49 AM





Copyright © 2019 My Math Forum. All rights reserved.